D. Correct one mistake in each sentence.
1. We were talking about an important exam when someone was entering our study room without knocking.
2. When the school bus arrived, I chatted with my friends.
3. James played basketball when he fell and hurt his ankle.
4. We were waiting anxiously while the teacher marked our exam papers.
1. We were talking about an important exam when someone entered our study room without knocking.
2. When the school bus arrived, I was chatting with my friends.
3. James was playing basketball when he fell and hurt his ankle.
4. We were waiting anxiously while the teacher was marking our exam papers.